Cov teeb meem kev siv tshuab hauv kev tsim cov silicon carbide wafers zoo uas ruaj khov thiab muaj kev ua tau zoo suav nrog:
1) Vim tias cov siv lead ua yuav tsum loj hlob hauv qhov chaw kaw kub siab tshaj 2000 ° C, qhov yuav tsum tau tswj qhov kub thiab txias yog siab heev;
2) Vim tias silicon carbide muaj ntau tshaj 200 cov qauv siv lead ua, tab sis tsuas yog ob peb cov qauv ntawm ib leeg-siv lead ua silicon carbide yog cov ntaub ntawv semiconductor xav tau, qhov sib piv ntawm silicon-rau-carbon, qhov kub thiab txias ntawm kev loj hlob, thiab kev loj hlob ntawm siv lead ua yuav tsum tau tswj hwm kom meej thaum lub sijhawm loj hlob ntawm siv lead ua. Cov kev ntsuas xws li qhov ceev thiab cua ntws siab;
3) Nyob rau hauv txoj kev sib kis ntawm cov pa dej, cov thev naus laus zis nthuav dav ntawm silicon carbide siv lead ua kom loj hlob yog qhov nyuaj heev;
4) Qhov nyuaj ntawm silicon carbide yog ze li ntawm pob zeb diamond, thiab kev txiav, sib tsoo, thiab kev txhuam hniav yog qhov nyuaj.
SiC epitaxial wafers: feem ntau yog tsim los ntawm kev siv tshuaj lom neeg vapor deposition (CVD). Raws li ntau hom doping, lawv tau muab faib ua n-hom thiab p-hom epitaxial wafers. Domestic Hantian Tiancheng thiab Dongguan Tianyu twb muaj peev xwm muab 4-nti / 6-nti SiC epitaxial wafers. Rau SiC epitaxy, nws nyuaj rau tswj hwm hauv thaj chaw muaj hluav taws xob siab, thiab qhov zoo ntawm SiC epitaxy muaj kev cuam tshuam ntau dua rau SiC cov khoom siv. Ntxiv mus, cov khoom siv epitaxial yog monopolized los ntawm plaub lub tuam txhab ua lag luam hauv kev lag luam: Axitron, LPE, TEL thiab Nuflare.
Silicon carbide epitaxialwafer yog hais txog silicon carbide wafer uas ib zaj duab xis siv lead ua ib leeg (txheej epitaxial) nrog qee qhov yuav tsum tau ua thiab zoo ib yam li cov siv lead ua substrate loj hlob ntawm cov silicon carbide substrate thawj. Kev loj hlob Epitaxial feem ntau siv CVD (Chemical Vapor Deposition,) cov khoom siv lossis MBE (Molecular Beam Epitaxy) cov khoom siv. Txij li thaum cov khoom siv silicon carbide raug tsim ncaj qha hauv txheej epitaxial, qhov zoo ntawm txheej epitaxial cuam tshuam ncaj qha rau kev ua tau zoo thiab cov txiaj ntsig ntawm lub cuab yeej. Raws li qhov hluav taws xob tiv taus kev ua tau zoo ntawm lub cuab yeej txuas ntxiv mus, qhov tuab ntawm txheej epitaxial sib xws ua tuab dua thiab kev tswj hwm nyuaj dua. Feem ntau, thaum qhov hluav taws xob nyob ib puag ncig 600V, qhov tuab ntawm txheej epitaxial xav tau yog li 6 microns; thaum qhov hluav taws xob nyob nruab nrab ntawm 1200-1700V, qhov tuab ntawm txheej epitaxial xav tau ncav cuag 10-15 microns. Yog tias qhov hluav taws xob ncav cuag ntau dua 10,000 volts, qhov tuab ntawm txheej epitaxial ntau dua 100 microns yuav tsum tau ua. Raws li qhov tuab ntawm cov txheej epitaxial txuas ntxiv mus, nws ua rau nyuaj rau tswj cov tuab thiab resistivity uniformity thiab defect density.
Cov khoom siv SiC: Thoob ntiaj teb, 600 ~ 1700V SiC SBD thiab MOSFET tau raug tsim kho. Cov khoom tseem ceeb ua haujlwm ntawm qib voltage qis dua 1200V thiab feem ntau txais TO ntim. Hais txog tus nqi, cov khoom SiC ntawm kev lag luam thoob ntiaj teb muaj tus nqi ntawm kwv yees li 5-6 npaug siab dua lawv cov Si counterparts. Txawm li cas los xij, tus nqi tab tom txo qis ntawm tus nqi txhua xyoo ntawm 10%. nrog rau kev nthuav dav ntawm cov ntaub ntawv upstream thiab cov khoom siv tsim khoom hauv 2-3 xyoos tom ntej, kev muab khoom lag luam yuav nce ntxiv, ua rau muaj kev txo nqi ntxiv. Nws xav tias thaum tus nqi ncav cuag 2-3 npaug ntawm cov khoom Si, qhov zoo uas coj los ntawm kev txo cov nqi system thiab kev ua tau zoo dua yuav maj mam tsav SiC kom nyob hauv qhov chaw ua lag luam ntawm Si cov khoom siv.
Cov ntim khoom ib txwm muaj yog ua los ntawm cov khoom siv silicon, thaum cov ntaub ntawv semiconductor tiam thib peb xav tau kev tsim tshiab kiag li. Kev siv cov qauv ntim khoom ib txwm muaj silicon rau cov khoom siv fais fab dav dav tuaj yeem ua rau muaj teeb meem tshiab thiab kev cov nyom ntsig txog zaus, kev tswj hwm thermal, thiab kev ntseeg tau. Cov khoom siv fais fab SiC muaj kev nkag siab ntau dua rau parasitic capacitance thiab inductance. Piv rau cov khoom siv Si, cov chips fais fab SiC muaj kev hloov pauv sai dua, uas tuaj yeem ua rau overshoot, oscillation, kev poob hloov pauv ntau ntxiv, thiab txawm tias cov khoom siv ua haujlwm tsis zoo. Tsis tas li ntawd, cov khoom siv fais fab SiC ua haujlwm ntawm qhov kub siab dua, xav tau cov txheej txheem tswj hwm thermal ntau dua.
Muaj ntau yam qauv sib txawv tau tsim nyob rau hauv thaj chaw ntawm kev ntim khoom siv hluav taws xob semiconductor dav dav. Cov ntim khoom siv hluav taws xob raws li Si ib txwm tsis haum lawm. Txhawm rau daws cov teeb meem ntawm cov yam ntxwv parasitic siab thiab kev ua haujlwm tsis zoo ntawm cov ntim khoom siv hluav taws xob raws li Si, cov ntim khoom siv hluav taws xob SiC siv cov kev sib txuas wireless thiab cov thev naus laus zis txias ob sab hauv nws cov qauv, thiab kuj siv cov ntaub ntawv substrate nrog kev ua kom sov zoo dua, thiab sim koom ua ke decoupling capacitors, kub / tam sim no sensors, thiab tsav circuits rau hauv cov qauv module, thiab tsim ntau yam thev naus laus zis ntim khoom sib txawv. Ntxiv mus, muaj cov teeb meem kev siv tshuab siab rau kev tsim khoom siv SiC thiab cov nqi tsim khoom siab.
Cov khoom siv silicon carbide yog tsim los ntawm kev tso cov txheej epitaxial rau ntawm silicon carbide substrate los ntawm CVD. Cov txheej txheem suav nrog kev ntxuav, oxidation, photolithography, etching, stripping ntawm photoresist, ion implantation, tshuaj vapor deposition ntawm silicon nitride, polishing, sputtering, thiab cov kauj ruam ua tom qab los tsim cov qauv ntaus ntawv ntawm SiC ib leeg siv lead ua substrate. Cov hom tseem ceeb ntawm SiC fais fab khoom siv suav nrog SiC diodes, SiC transistors, thiab SiC fais fab modules. Vim yog cov yam xws li qeeb qeeb upstream khoom tsim tawm thiab cov nqi qis, silicon carbide khoom siv muaj cov nqi tsim khoom siab.
Ntxiv rau, kev tsim khoom siv silicon carbide muaj qee qhov teeb meem kev siv tshuab:
1) Nws yog qhov tsim nyog los tsim ib qho txheej txheem tshwj xeeb uas sib xws nrog cov yam ntxwv ntawm cov ntaub ntawv silicon carbide. Piv txwv li: SiC muaj qhov chaw yaj siab, uas ua rau cov thermal diffusion ib txwm tsis ua haujlwm. Nws yog qhov tsim nyog los siv txoj kev doping ion implantation thiab tswj cov kev ntsuas xws li kub, cua sov, lub sijhawm, thiab roj ntws; SiC yog inert rau cov tshuaj solvents. Cov txheej txheem xws li qhuav etching yuav tsum tau siv, thiab cov ntaub ntawv npog ntsej muag, cov roj sib xyaw, kev tswj hwm ntawm sidewall slope, etching rate, sidewall roughness, thiab lwm yam yuav tsum tau optimized thiab tsim;
2) Kev tsim cov hlau electrodes ntawm silicon carbide wafers xav tau kev tiv thaiv kev sib cuag hauv qab 10-5Ω2. Cov khoom siv electrode uas ua tau raws li qhov yuav tsum tau ua, Ni thiab Al, muaj kev ruaj khov thermal tsis zoo tshaj 100 ° C, tab sis Al / Ni muaj kev ruaj khov thermal zoo dua. Kev tiv thaiv kev sib cuag tshwj xeeb ntawm / W / Au composite electrode khoom yog 10-3Ω2 siab dua;
3) SiC muaj kev hnav khaub ncaws siab, thiab qhov nyuaj ntawm SiC yog qhov thib ob tsuas yog pob zeb diamond, uas tso tawm cov kev xav tau siab dua rau kev txiav, sib tsoo, polishing thiab lwm yam thev naus laus zis.
Ntxiv mus, cov khoom siv fais fab trench silicon carbide nyuaj rau tsim. Raws li cov qauv khoom siv sib txawv, cov khoom siv fais fab silicon carbide tuaj yeem faib ua cov khoom siv planar thiab cov khoom siv trench. Cov khoom siv fais fab planar silicon carbide muaj qhov sib xws zoo thiab cov txheej txheem tsim khoom yooj yim, tab sis lawv yooj yim rau JFET nyhuv thiab muaj lub peev xwm parasitic siab thiab kev tiv thaiv on-state. Piv nrog cov khoom siv planar, cov khoom siv fais fab trench silicon carbide muaj qhov sib xws qis dua thiab muaj cov txheej txheem tsim khoom nyuaj dua. Txawm li cas los xij, cov qauv trench yog qhov zoo rau kev nce qhov ceev ntawm cov khoom siv thiab tsis tshua muaj peev xwm tsim cov nyhuv JFET, uas yog qhov zoo rau kev daws teeb meem ntawm kev txav mus los ntawm channel. Nws muaj cov khoom zoo heev xws li me me on-resistance, me me parasitic capacitance, thiab kev siv hluav taws xob tsawg. Nws muaj cov txiaj ntsig zoo ntawm tus nqi thiab kev ua tau zoo thiab tau dhau los ua qhov kev taw qhia tseem ceeb ntawm kev txhim kho cov khoom siv fais fab silicon carbide. Raws li Rohm lub vev xaib official, ROHM Gen3 qauv (Gen1 Trench qauv) tsuas yog 75% ntawm Gen2 (Plannar2) thaj chaw chip, thiab ROHM Gen3 qauv on-resistance raug txo los ntawm 50% nyob rau hauv tib lub chip loj.
Cov nqi siv rau silicon carbide substrate, epitaxy, front-end, R&D thiab lwm yam suav txog 47%, 23%, 19%, 6% thiab 5% ntawm cov nqi tsim khoom ntawm silicon carbide li.
Thaum kawg, peb yuav tsom mus rau kev rhuav tshem cov teeb meem kev siv tshuab ntawm cov khoom siv hauv cov saw hlau silicon carbide.
Cov txheej txheem tsim cov silicon carbide substrates zoo ib yam li cov silicon-based substrates, tab sis nyuaj dua.
Cov txheej txheem tsim khoom ntawm silicon carbide substrate feem ntau suav nrog cov khoom siv raw synthesis, crystal growth, ingot processing, ingot cutting, wafer grinding, polishing, cleaning thiab lwm yam kev sib txuas.
Cov theem loj hlob ntawm cov siv lead ua yog lub hauv paus ntawm tag nrho cov txheej txheem, thiab cov kauj ruam no txiav txim siab cov khoom hluav taws xob ntawm cov silicon carbide substrate.
Cov ntaub ntawv silicon carbide nyuaj rau loj hlob hauv cov kua theem nyob rau hauv cov xwm txheej ib txwm muaj. Txoj kev loj hlob theem vapor nrov hauv kev ua lag luam niaj hnub no muaj qhov kub loj hlob siab dua 2300 ° C thiab xav tau kev tswj hwm qhov kub loj hlob kom meej. Tag nrho cov txheej txheem ua haujlwm yuav luag nyuaj rau saib. Qhov yuam kev me me yuav ua rau cov khoom pov tseg. Piv txwv li, cov ntaub ntawv silicon tsuas yog xav tau 1600 ℃, uas qis dua. Kev npaj cov khoom siv silicon carbide kuj ntsib teeb meem xws li kev loj hlob qeeb qeeb thiab cov qauv siv lead ua siab. Kev loj hlob ntawm silicon carbide wafer siv sijhawm li 7 txog 10 hnub, thaum rub cov pas nrig silicon tsuas yog siv sijhawm 2 thiab ib nrab hnub. Ntxiv mus, silicon carbide yog cov khoom siv uas nws qhov nyuaj yog qhov thib ob tsuas yog pob zeb diamond. Nws yuav poob ntau thaum txiav, sib tsoo, thiab polishing, thiab qhov piv ntawm cov zis tsuas yog 60%.
Peb paub tias qhov sib txawv yog kom nce qhov loj ntawm cov silicon carbide substrates, thaum qhov loj txuas ntxiv mus, qhov yuav tsum tau ua rau cov thev naus laus zis nthuav dav dav dua thiab siab dua. Nws xav tau kev sib xyaw ua ke ntawm ntau yam kev tswj hwm kev tswj hwm kom ua tiav kev loj hlob ntawm cov siv lead ua.
Lub sijhawm tshaj tawm: Tsib Hlis-22-2024